How do you catch a killer when it appears that the criminal isn't even human? That's what the detectives have to figure out on the upcoming
"Castle" episode, "The Human Factor." After a man is somehow killed by a drone attack, finding the actual person responsible is very, very tricky.

See just how tricky it is in these three video clips from the episode.

The death in this episode doesn't look like one that either Castle (
Nathan Fillion) or Beckett (
Stana Katic) can take lightly. They can't even make jokes or crazy theories about the military taking out the victim.

Could the military do something like that? It's definitely best to hope that the answer is no.

Fortunately, humor returns by the time we get to the next clip. The detectives need to figure out who -- if anyone -- was piloting the drone that committed murder. Castle, naturally, has the most entertaining theory.

Is it so far-fetched to go with computers achieving consciousness and turning against their creators? This is TV, after all. Many weirder things have happened -- like a writer being allowed to hang out with cops for five years ...

The really funny thing is that Castle always believes his own crazy theories on some level. That's the only explanation for his reaction in the final clip from "The Human Factor."

You know, even though this was just a silly prank from Beckett and even though Castle should have known better, toys coming to life and attacking are scary. What would any of us do if attacked by playthings in the middle of the night?